KR100551164B1 - Method for controlling link state of V5.2 protocol - Google Patents

Abstract

The present invention is to control the link state of the V5.2 protocol, the present invention is a V5.2 protocol in which the Layer 1 link FSM and the physical link is separated, the event is inspected at regular intervals, the event check result is abnormal or Sa7_0 In normal state, all inspected events are reported from the physical layer to the Layer 1 Link FSM immediately after they occur, and if the event check results in Sa7_1 is healthy, events other than Sa7_1 are reported from the physical layer to the Layer 1 Link FSM immediately. By changing the status and reporting Sa7_1 to the Layer 1 Link FSM whenever the normal state of Sa7_1 reaches a certain time, the system improves system performance by preventing the LSM from sending unnecessary Sa7_1 to the Layer 1 Link FSM in the normal state. And excellent portability between physical layers.

Description

Method for controlling link state of V5.2 protocol             

1 is a block diagram of a link control function model of a conventional V5.2 protocol;

2 is a block diagram showing a link control function model of the V5.2 protocol to which the present invention is applied;

3 is a flowchart illustrating a link state control method of a V5.2 protocol according to the present invention;

4 is a transition diagram showing the link state transition shown in FIG.

<Explanation of symbols for the main parts of the drawings>

30: CSB 31: System Management

32: layer 1 link FSM 33: layer 3

40: network router 50: VSIA

The present invention relates to link control of the V5.2 protocol. In particular, the V5.2 protocol improves the performance of the V5.2 interface by controlling the link state according to the separation of the layer 1 link finite state machine (FSM) and the physical link. A link state control method of the V5.2 protocol to provide excellent portability between physical layers.

1 is a block diagram of a link control function model of a conventional V5.2 protocol. This is the same as G.965 (V5.2) Chapter 16 Link Control Requirements Specification of ITU-T (International Telecommunications Union, Telecommunication Sector). .

The functional model of FIG. 1 shows that Layer 1 link FSM 12, 22, which is directly related to the interface signal, automatically operates from link control functions and procedures. It is the responsibility of link control to coordinate Layer 1 links and link control procedures, so System Management should always monitor the status of these links.

Communication between each link control FSM (11) 21 and Layer 1 link FSM (12) (22) is provided through a management primitive (MPH), the communication of the system management and link control FSM (11) (21) is managed. This is done using data units (MDUs). It is delivered by Layer 3 protocol for communication with the Power Link Control FSM. There is also an MDU transmitted from the link control protocol entity to system management to support protocol error handling procedures.

The layer 1 link FSM 12, 22 layer automatically operates according to the layer 1 signal to confirm the layer 1 link status to the link control FSM 11, 21 by the MPH-DI and the MPH-AI. Layer 1 status is detected on both sides of the Layer 1 link interface. Due to the fact that the predefined persistence check timer may have different values in LE and AN, the indication to the link control FSM may be at different points in time. The resulting problems are considered in the definition of the link control FSM.

It is the responsibility of the LE's system administration to determine which link operation should be initiated after a link identification procedure is not applied and Layer 1 recovers from a failure state (link control FSM generates MDU-LAI) or after successful link identification. .

And link state management in the V5.2 interface layer 1 link FSM (12) (22) is described in detail as follows. First, three implementation schemes have been identified for the detection reporting of events forwarded from the layer-1 link FSM 12 (22) to system management and for the determination of the resulting behavior.

1) Immediately report to management (MPH-EIe) to record detected events, and process to evaluate the interface status with respect to the resulting actions on the service and other FSMs. In this case, the system managers 11 and 21 continuously carry out the investigation necessary for the reported event to identify whether the interface is in an operating state or an inactive state.

2) Immediately report (MPH-EIe) to system management 11 (21) to record the detected event. Layer 1 continuously conducts investigations to assess interface status, and as a result, status reporting to management (MPH-AI in MAN and LE, MH-DI).

3) Combination of 1) and 2)

The persistence check timers for AN and LE are predefined in 100ms increments from 100ms to 25s. Persistence check timer has a tolerance of ?? 50ms for nominal values from 100ms to 1s, and has a tolerance of ?? 10% over 1s.

Layer 1 link FSM 12 (22) does not perform any operation with the link control FSM for the link identification procedure. This is to avoid false information that can appear when bit errors or co-ordination problems occur. The operation required for the link control FSM 11, 21 is controlled by the appropriate control function from the link control FSM 11, 21. FIG. If the Layer 1 link FSM 12 (22) is in the 1 state (after successful execution of the defined persistence check procedure) and detects that the Sa7 bit is ZERO, the FSM enters state 5.2 and the result of the persistence check procedure. Keeps the information available as long as it remains unchanged. If the link control FSM 11 (21) requests link identification information using the MPH-IDR, the layer 1 link FSM 12 (22) responds using the MPG-IDI in this case. If not, respond with MPH-EIg. MPH-EIg represents a link identification disorder. If the layer 1 link FSM 12 (22) is one of the non-operating states 2 through 4, no link identification is possible. Therefore, this situation is notified to the link control FSM 11 (21) in response to the MPH-DI.

When the Layer 1 link FSM 12 (22) receives the MPH-ID in State 1 or 5.2, it enters State 5.1 and sets the Sa7 bit in the transmitting bit stream to zero. Upon receipt of the MPH-NOR in State 5.1, the FSM returns to State 1. That is, the Sa7 bit is set to 1. Upon detection of the failure condition, the system returns to the appropriate state and transmits the relevant signal according to the current Layer 1 link interface condition.

As described above, the layer 1 link FSM 12 (22) is required to manage the state of the E1 link. When a problem occurs in the link, the system can be stabilized by reporting the state to the system management as soon as possible.

However, what is provided in the ITU-T G.965 specification describes the algorithm in which the event occurred. In other words, the ideal method is presented regardless of the environment of the system.

Therefore, in the conventional V5.2, the maximum number of links per interface is set to 16. If all the links are provided on one board, it is difficult to implement the protection protocol provided by Layer 3 as well as system redundancy. Providing 16 physical layers per board is an impractical implementation in a real system.

Accordingly, the present invention has been proposed to solve the above conventional problems, and an object of the present invention is to control the link state according to the separation of the layer 1 link FSM and the physical link in the V5.2 protocol. It is to provide a link state control method of the V5.2 protocol that can improve performance and provide excellent portability between physical layers.

In order to achieve the above object, the link state control method of the V5.2 protocol according to the present invention,

If the event is inspected at regular intervals and the event check result is abnormal or Sa7_0 is in a normal state, all inspected events are reported to the layer 1 link FSM in the physical layer immediately after the occurrence of the state change, and the event check result Sa7_1 is in a normal state. If the event excluding Sa7_1 occurs, the physical layer reports the layer1 link FSM to the layer1 link FSM immediately after its occurrence, and reports Sa7_1 to the layer1 link FSM whenever the normal state of Sa7_1 reaches a predetermined time. It is characterized by the configuration.

Hereinafter, an embodiment according to the technical spirit of the link state control method of the present invention V5.2 protocol will be described in detail with reference to the accompanying drawings.

In order to solve the conventional problem, the present invention operates in a device in which a board on which a layer 1 link FSM is mounted and a board providing a physical layer are separated. There is a need for a method according to the invention for state management of links on a physical layer board. 2 is a block diagram showing a link control function model of the V5.2 protocol to which the present invention is applied.

As shown here, the system management 31, the layer 1 link FSM 32, and the layer 3 33 are provided to check the link status of the VSIA 50, and the event is transmitted to the layer 1 link FSM 32. Call Signaling Board (CSB) 30 to report to; A network router 40 connecting the CSB 30 and the VSIA 50 to perform a routing function; It is composed of a VSIA (Vocoder Selector Interface Assembly) 50 connected to the network router 40 and equipped with a link status management process (LSM) that manages link status and provides a physical layer.

The events provided by the specification are as follows.

First, an event transmitted from the layer-1 link FSM 32 to the LSM 50 of the VSIA is as follows.

MPH-ID: For transmitting the Link Identification signal, when the LSM 50 receives this signal, it sets the Sa7 bit to zero.

MPH-NOR: To stop the Link Identification signal. When the LSM 50 receives this signal, it sets the Sa7 bit to 1.

MPH-STOP: Stops error status report.

MPH-PROCESS: Status report is reported normally.

Meanwhile, events transmitted from the LSM 50 of the VSIA to the layer 1 link FSM 32 are as follows.

MPH-EIa ~ EIf: Error status

MPH-SA7_0: Sa7 bit received in link TS (Time Slot) 0 is 0

MPH-SA7_1: Sa7 bit received from link TS0 is 1

3 is a flowchart illustrating a link state control method of a V5.2 protocol according to the present invention.

As shown therein, step ST1 of inspecting the event at regular intervals; When the event check result is abnormal or Sa7_0 is in a normal state, reporting all checked events to the layer 1 link FSM 32 at the physical layer and performing a state change immediately after occurrence (ST2 to ST11); If Sa7_1 is in the normal state, the event except for Sa7_1 is reported to the layer 1 link FSM 32 from the physical layer immediately after the occurrence of the state change, and whenever the normal state of Sa7_1 reaches a predetermined time, the layer Reporting the Sa7_1 to the one-link FSM 32 (ST12 ~ ST18) is performed.

4 is a transition diagram showing the link state transition shown in FIG.

In FIG. 4, E means an abnormal state, N0 means Sa7_0 is in a normal state, and N1 means Sa7_1 is in a normal state. T1 is an event check timer and T2 is a reporting timer of Sa7_1.

Thus, the LSM 50 starts with the E state at power-on, and counts the event check timer T1 to check the event at regular intervals. As a result of the event inspection, in the E state which is an abnormal state and the N0 state where Sa7_0 is a normal state, all inspected events are immediately reported from the LSM 50 having the physical layer to the layer 1 link FSM 32 of the CSB 30. The state changes according to the state transition diagram of four.

In addition, if the event check result Sa7_1 is in the normal state N1 state, events other than Sa7_1 immediately report the LSM 50 to the layer 1 link FSM 32 to change the state. The LSM 50 counts T2, which is a reporting timer of Sa7_1, and reports Sa7_1 to the layer-1 link FSM 32 whenever the state of N1 duration without interruption becomes a multiple of T2.

T1 is determined by the LSM 50 according to the performance of the system.

Since the state of N1 is a normal state, when the state persists, the LSM 50 reports Sa7_1 received on the TS0 channel of the link to the layer 1 link FSM 32 every time T1, which may put a burden on the operation of the system. . So using T2 can contribute to the performance of the system depending on the value of T2.

As such, the present invention controls the link state according to the separation of the layer 1 link FSM and the physical link in the V5.2 protocol.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. That is, in all fields using the V5.2 protocol, the system can be applied to a system in which a layer 1 link FSM and a physical layer are mounted on different boards. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the link state control method of the V5.2 protocol according to the present invention can improve the performance of the system by preventing the LSM from transmitting unnecessary Sa7_1 to the layer 1 link FSM in the normal state. The effect is to provide excellent portability of the liver.

Claims (1)

In a link state control method of a V5.2 protocol in which a layer 1 link finite state machine (FSM) and a physical link are separated, Inspecting the event at regular intervals; If the event check result is abnormal or Sa7_0 is in a normal state, reporting all checked events from the physical layer to the layer 1 link FSM immediately after occurrence and performing a state change; If Sa7_1 is in the normal state, the event except for Sa7_1 is reported to the layer1 link FSM from the physical layer immediately after occurrence, and the state is changed. When the normal state of Sa7_1 becomes a predetermined time, the layer1 link FSM Link status control method of the V5.2 protocol, characterized in that the step of reporting the Sa7_1.

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